Regarding your wife's unwillingness to admit affair was wrong, even Michelle and DB team (which are big on patience) will say that remorse and being able to say your sorry is key for reconciliation.
If the affair was not wrong, then what your wife (and my wife) is saying is, "It's OK for me to stray when I'm not feeling connected to you." There is no covenant, commitment or promise aside from, "I'll be faithful to you as long as I feel like it." Well, that's fine in dating, but not in a marriage.
Some say that it's kindness that leads to repentance. And perhaps it takes re-connection, love and the lifting of the fog for the wayward spouse to say they are sorry and the affair was wrong. But, virtually EVERY book on the subject require some measure of remorse and an admission of guilt.
My therapist put it differently. He said living with an unrepentant adulterer is like living with a member of the mob. You need to pretend everything is OK, but the person you live with murders people for a living and thinks nothing of it. You either need to be afraid, amoral or insane to ignore that.
